The present invention relates to the medical arts. It finds particular application in conjunction with a device for controlling the amount and rate of an administered dose of liquid. However, it is to be appreciated that the present invention will also find application in conjunction with other systems requiring delivery of selected amounts of a fluid.
It frequently happens in medical technology that additional doses of small amounts of liquids need to be added, for example in an inhalator to the flow of oxygen, over a certain period of time or in a specified dosage to the infusion solution of an infusion apparatus. Similar problems occur also in other areas of technology when relatively small amounts of liquids need to be added or applied.
According to the invention, the solution is taking advantage of the technology which was developed for ink jet printers. An ink jet print head has a multitude of jets (for example 12-300), which are connected with an ink reservoir. Each jet is assigned a thermo-electrical or piezo-electrical converter. The converters are individually controlled by the printer and expel a volume of ink from the respective jet during actuation.
It was possible to ascertain through tests that when a great many droplets are expelled, the droplet mass, on average, remains almost constant. Therefore, this principle is suitable also for dosing of medicaments.